Electromagnetic device



Patented May 5, 1925.

UNITED STATES maar y' PA'rENTl ortica.

JACOB R. FRY, F NEV YORK, N. Y., ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, 0F NEW YORK, N. Y., A CORPORATION OF NEW YORK.

ELECTROMAGNETIC DEVICE.

appncatien filed Maren 24, 1921. serial No. 455,084.

To all whom t may concern:

Be it known that I, JACOB R. FRY, a citizen of the United States, residing at New York, in the county of Bronx, State of New York, have invented certain new and useful Improvements in Electromagnetic Devices, of which the following is a full, clear, concise, and exact description.

This invention relates to relays and particularly to relays of the electromagnetically polarized type. l

The object of this invention is to provide a compact electromagnetic device having a plurality of windings with provision for connection of supply current at certain points to cause the :device to function as a polarized relay responsiveto direct current impulses of certain polarity or to alternating current energization, dependent on the nature of the current supply and method of itsconnection to the device.

A feature of this invention resides in an electromagnetic structure comprising axpair of E-sha ed cores of magnetic material with a plurallty of electrically continuous windings thereon and an armature memberadapted to move in the space between said E-v shaped cores to control circuit Contact inembers associated therewith. The particular 3 design of the yokes yincluded in the magnetic structure employed in this inventiony makes the cores and armature associated therewith magnetically short, thereby greatly increasing the self-demagnetizing factor, that is, the ratio of the length of the magnetic path in iron to the cross section of the core.

This self-demagnetizing characteristic is very desirable in relays and particularly in relays used in telephone systems" wherein the electromagnets are designed, in most cases, to operate on predetermined current values, so that anyprevious applicationI of a magneto-motive force should, in no way, establish magnetic conditions in the relay, which would aifect its operation upon a subsequent energization. The device of this invention is particularly characterized by its combination of electric and lmagnetic circuits, wherein the electric circuits are Vsuch as to produce one magnetic flux in a circuit cutting throughthe armature at right angles thereto and a second magnetic flux in circuits including the armature as a path for this flux in opposing directions in the adjacent parts of said armature. This device is also characterized by its eiicient adaptation to use in a variety of circuits dependent on the'nature of current supply and the method of connection of that supply to the energizing windings. For eX- ample, with a source of direct current properly connected to certain points in the windings, the device becomes a polarized relay and will respond to operating current impulses of certain polarity sent over a circuit connected at certain `other points of the winding. In this case, the same windings are used for polarization and operation. If alternating current be applied at certain points in the winding and an auxiliary alternating current, in phase. and cf like frequency with the first mentioned alternating current, be applied at certain other points in the windings, the device operates in one direction during the period of application of the current. Direction of operation may be reversed .by reversing the connection of the auxiliary alternating current.

A more complete yunderstanding of these and other novel features may be had from the accompanying illustrative drawings and detailed description, in which Figure 1 discloses a perspective view of the device of this f application with the energizing "coils shown 85 in section and the flux paths for contemplated circuits indicated on the two r2-shaped magnetic cores. y

Figure 2 discloses a circuit diagram of one embodiment of this invention, showing the relation of current flow to magnetic flux for operation of the armature, where the polar` izing current and operating current are equal in amount. y

Figure 3 is a modification ofFigure 2 and g5 diagrammatically illustrates the current relations in the windings of this relay when polarized with direct current operated by current pulses over a second circuit.

Figure 4 discloses a diagram of circuit rem@ lations for this relay for sustained operation. when used in an alternating current circuit.

In detail there is disclosed in Figure 1,

a pair of E-shaped magnetic cores 1 and 2 arranged with the end faces of similar mem? 105 bers, end adjacent. On the central member of core 1 is a pair of energizing coils 3 and .4 and onthe central member of core 2 is another pair of energizing coils 5 and 6. Though the coils are disclosed associated im with the central member of each core, it is obvious that they may be associated with 'other portions of the cores without alteration of the magnetic circuits. Located .intermediate the adjacent end faces mentioned, is an armature 7 arranged' to be mounted in trunnion bearings in the rear of the cores 1 and 2.- This bearing is not disclosed in the drawing as its nature is well-known. The windings 3, 4, 5 and 6, when properly connected to each other and to a source of electrical energy set up magnetic flux ain the paths shown in dash lines. It is to be noted, that this magnetic flux passes through the armature perpendicular to its length atthree well defined locations on the armature, these locations being limited tothe extent of the face of each magnetic core member. A sprng8 is disclosed as attached to the arma- `ture in such a position as to maintain the armature substantially lnid-way between the A magnetic cores 1 and 2 when the device is in its unoperated position. However it is to be understood that the spring may be atv tached at any appropriate point to create a retractile moment, or the armature may be of the reed type, in which case 'it is self retracting. lAttached on one end of the armature is an insulating pin 9 cooperable with spring contact members 10, 11, 12 and 13, which members are electrically insulated from each other by insulating members `14 and are rigidly retained` by a clamping means. It is toL e noted that the magnetic cores 1 and 2 are disclosed as laminated in structure to prevent eddy current losses when the relay is used on alternating` current circuits. Also it is to be expressly understood that spring. 8 while disclosed as a spiral tension spring, may assume any form well-known and well adapted for the purpose intended and that insulating pin 9 and cooperable contact members 10, 11, 12 and 13 may be arranged in other positions cooperable with the armature to produce the same result as shown.

Referring to Figure 2 in' detail, the apparatus of Figure 1 is shown in outline and the electric and )magnetic circuits are `shown yfor a condition of operation resulting from connection of a source of electrical energy 15 to two symmetrically opposite points in the closed coil circuit, and the connection of a second source of electrical energyassociated with line wires 16 and 1T to the two remaining symmetrically opposite point-s in the coil circuit; this last mentioned source of electrical energy resulting in a flow of electric current being of the same amountl as that sent out by source 15. Electrical source 15 for present discussion may be called the polarizing battery this source, ond source of electrical energy may be called the operating source of energy and its current and the current flowing from the polarizing current; the sec- Starting with the the same positive terminal of battery 15, current may be traced through windings 6 and 4 and back to the negative terminal of the battery 15. The direction of this current flow is indicated in dash lines with arrow points properly placed. Current from the second electrical source which has been termed the operating current may be traced as coming in over line 16, through coils 3 and 6, and returning over line 17. ,Another and parallel path for this operating current may be traced from line 16 through coils 5 and 4 and returning over line 17. This operating current is indicated. by solid lines with arrow points properly placed near the wires.l Considering the polarizing and operatingcurrents as indicated in the diagram, it will be Seenthat the conditions established in the above discussion will cause the two currents mentioned to nullify each other in coils 3 and 4 and to become additive in coils 5 and 6 with the result vthat no magnetic ilux will be produced in any possible circuit in magnetic core 1, but that strong magnetic iiux due to the combination of currents mentioned will be established in magnetic core 2, as disclosed in the diagram. Itwill'be noted reverses the direction of operating current in the coils connected therewith. According to the usual laws of magnetic attraction the armature is drawn toward the strongestv magnetic lield. Thus selective operation in the relay is dependent only on the direction of flow of the operating current, assuming the polarizing4 currentfrom source 15 to remain constant in direction. If the operating current be greater or less in amount than the polarizing current two complete sets of flux paths will be established but there will always be a preponderance yof iiux on one side or the other of the armature dependent on the relative directions of the polarizing and operating currents. Thus, the amount of current flow has no effect on the -placement of the effective operating iiu-X'but only aiiects the amount of that iiuX.V Theplacement of the effective ,operating flux is dependent entirely on the relative directions of polarizing and operating current flow; It is obvious from a `study'of the diagram in Figure2 that the connections of polarizing and operating current- .may be interchanged without affecting the operation of the relay.

Figures 3 ande: illustrate diagrammatically the electric circuits desirable for operation of the relay of this invention'on direct current and on alternating current respectively, though it is apparent that the arrangement shown yin Fig. 3 would operate on a combination of both direct vand alternating currents, by the application of an alternating current source across the conductors 16 and 17. Referring particularly to Figure 4 there is disclosed a source of alternating current 18 connected to wires 16 and 17 and the said wires are connected to symmetrically opposite points in the closed coil circuit including coils 3, 5, l and 6. The primary winding 19 of a transformer is connected in series in line 17 and the secondary winding 2O of the said transformer has lits terminals connected to the two remaining symmetrically opposite points in the relay coil circuit. With circuit connections as disclosed, the passage of alternating current over the wires 16 and 17 will induce a current in the secondary winding circuit 20 of the transformer substantially in time phase with the alternating current source. In the case of this circuit, it will be convenient to consider the current flowing over the line wires 16 and 17 and through the primary winding 19 of the trans- 'former as the polarizing current and the current flowing in the secondary winding 2() of the transformer as the operating current. Since it is obvious that the currents in the polarizing and operating circuits re- -verse their direction of iow'at the same of current flow in the electrical circuit dia-v gram of Figure 4,' if the transformer connections associated with windingsv 19 and 2O be substituted for a sourceof direct current [supply 15 shown in Figure 2.

What is claimed is: y

1. In combination, a pair `of E-shaped cores having corresponding members end adjacent, an armature 'cooperable with said magnetic cores in the space between said end adjacent members, windings yfor'said magnetlc cores,`said windings so connected as to form a closed series circuit, a source of electrical energy connected to sy1 nmetriy cally opposite points in said series connected winding4 circuit, a second source of electrical said cores, windings on said cores so con-v nected to each other and to a source of elecm trical energy that magnetic flux is produced in one direction throughout the adjacent middle members of said cores and in the opposite direction throughout the adjacent end members of said cores, cutting through the armature and at right angles thereto.

3. In an electromagnetic structure, a pair of E-siaped magnetic cores 'with corresponding members end adjacent, an armature cooperative therewith in the lspace be- 'tween ysaid cores, windings on said cores so connected to each other and Ito two sources of electrical energy that magnetic iux is produced in one direction in the middle member of one core, in the/opposite direction in the end members of thesame core and in opposing directions in the armature 4. In an electromagnetic structure, a pair of Efshaped magnetic cores with corresponding members end adjacent, an armature cooperative therewith in the spacebetween said cores, windings on said cores so connected to each other and totwo sources of electrical energythat magnetic ux is produced in one direction throughout the adjacent middle members of said cores and in the opposite direction throughout the adjacent end members of said cores cutting thi-'ou h the armature at right angles thereto and a second flux is produced including the members of one core only in the same direction as the first mentioned flux and the two halves of the armature in opposing direct-ions as a portion of thereturn circuit.

5. A relay comprising two yokes having their poles facing each other, anA armature positioned between said cles, windin s for each of said yokes, a pa1rv of termina s for the windings connected to a direct current source, and a second pair of terminals for f said windings connected to an alternating current source, said windin s being so related to said terminals that both direct and alternating current flow through both windings, said terminals connected to thedirect current source being conjugate to the ter; minals connected to the alternating current source.

6. A relay comprising two yokes having their poles facing each other, an armature positioned between said poles, windings for each of said yokes, a pair of terminals for the windings connected to a direct current source, a second pair of terminals for said windings connected to an alternating current source,said windings being so related to said terminals that both direct and alternating current flow through both windings,

*n said terminals connected to the alternating current source bein'gconjugate tol the terminals connected to the direct current 7. A relay comprising two yokes having their poles facing each other, a winding for each yoke connected in bridged relation to the opposite yoke, an armature positioned between said yokes and controlled by the electromagnetic condition thereof, a source of alternating current, a source of direct current and terminals for interchangeably Vconnecting said windings with either of said sources of current whereby said armature is caused to assume a neutral positionbetween thevpoles of said yoke.

In witness whereof I hereunto subscribe my name this 2l day of March, A. D.; 1921.

JACOB R. FRY. n 

